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Optimalizace tvaru drážky asynchronního motoru / Rotor Slot Shape Optimization of an Induction MachineSzekeres, Vojtech January 2016 (has links)
This thesis is dealing with optimization by using artificial intelligence of an induction machine rotor slot. The one optimized is commonly manufactured induction motor with simple deep bar rotor. Goal is to design an optimization method and achieve the highest possible value of efficiency and power factor of chosen machine. Work contains the parametric model construction in Ansys Maxwell software, the optimization algorithm assembly and its setup for desirable output, and processing of the results.
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Cryptographie homomorphe et transcodage d’image/video dans le domaine chiffré / Homomorphic encryption and image/video transcoding in the encrypted domainNokam Kuaté, Donald 14 December 2018 (has links)
L'apparition de nouvelles technologies comme l'informatique en nuages (cloud computing) offre de nouvelles opportunités de traitement de l'information. Par exemple, il est désormais facile de stocker ses photos ou vidéos personnelles sur des serveurs distants. Il est également possible de partager ces contenus à travers ces mêmes serveurs, ou encore via les réseaux sociaux ou les plateformes de téléchargement. Cependant, ces données personnelles sont bien souvent accessibles par le fournisseur de service, essentiellement pour des raisons pratiques : par exemple adapter une vidéo pour qu'elle s'affiche au bon format quel que soit l'appareil utilisé pour la visionner, permettre le partage de ses contenus avec d’autres personnes, etc. Cela soulève cependant un problème de confidentialité de ces données personnelles, et de confiance dans le fournisseur du service. La cryptographie classique apporte des solutions à ce problème, mais soulève malheureusement celui de la maniabilité des données : il devient par exemple impossible d'adapter un contenu vidéo au bon format d'affichage puisque le fournisseur ne peut plus « voir » la vidéo. Une solution alternative réside toutefois dans le chiffrement homomorphe. Cet outil un peu magique de la cryptographie avancée apporte la même sécurité que les algorithmes de cryptographie classique, mais permet de plus de manipuler les données tout en conservant leur forme chiffrée. Il offre ainsi une nouvelle perspective pour les fournisseurs puisque ceux-ci peuvent continuer à traiter l'information sans être capable de la voir, et donc sans atteinte à la vie privée de leurs utilisateurs, se conformant ainsi au nouveau Règlement Général sur la Protection des Données (RGPD). Bien que le chiffrement homomorphe soit très souvent considéré comme insuffisamment mature, du fait de sa complexité algorithmique, cette thèse cherche à montrer son caractère prometteur, en s'intéressant à son usage pour le traitement d'images et de vidéos chiffrées à la source. Nous regardons ainsi les différents algorithmes qui constituent un encodeur d'image/vidéo (JPEG/H264 et HEVC) et les transformons en des circuits qui sont manipulables par des systèmes de chiffrement homomorphes. Nous proposons ainsi dans cette thèse le tout premier pipeline de compression d'images de type JPEG ("homomorphic-JPEG") sur des pixels qui sont chiffrés de bout-en-bout. Pour optimiser la gestion des données ainsi protégées, nous proposons également de nouveaux outils applicables à tous les schémas de chiffrement homomorphe sur les réseaux idéaux. Notre approche permet de maximiser le nombre de slots dans un chiffré et introduit de nouvelles fonctions pour manipuler ces différents slots de manière indépendante les uns des autres. Ces travaux de thèse ont abouti à la publication de deux articles dans des conférences internationales ainsi qu’à la soumission d'un article supplémentaire. / The emergence of new technologies like cloud computing brings new opportunities in information processing. For example it is easy today to send our personal pictures or videos to a remote server (Google Drive, OneDrive …). We can also share this content among the same servers or via social networks and streaming services. However, this personal data is often also available to the service provider, mainly for practical reasons e.g. to configure a video to have the right format regardless of the displayer (smartphone or computer), to share our data with other people, etc. This raises issues of privacy and trust into the service provider. Classical cryptography brings some answers to this kind of issues, yet leaving the problem of handling the encrypted data: e.g., it becomes impossible to reconfigure a video because the provider can no longer “see” it. An alternative solution is “homomorphic encryption”. It is a powerful tool of advanced cryptography which provides the same security as classical cryptography algorithms, but it still allows us to manipulate ciphertexts such their underlying plaintexts are modified. Consequently, it offers a new perspective to service providers since they can continue to process their clients’information without knowing what it contains. This allows them to provide privacy-preserving services and comply with the new General Data Protection Regulation (GDPR). Although it is considered that homomorphic encryption does not have enough maturity due to its large algorithmic complexity, in this thesis, we are trying to show its potential by using it in the context of image and video processing over the encrypted data. In this context, we look at the different algorithms in an image/video encoder (JPEG/H264 and HEVC) and transform them to circuits which can be manipulated by homomorphic encryption schemes. Our main contribution is to propose the first pipeline for an image compression of type JPEG (homomorphic-JPEG) running on end-to-end encrypted pixels. To optimize the management of the encrypted data, we also propose new tools applicable to existing homomorphic encryption schemes over the ring version of lattices. Our approach allows us to maximize the number of slots in some ciphertext and we introduce new functions allowing to handle these slots independently in the encrypted domain. This thesis work also lead to two publications to international conferences as well as the submission of an additional article.
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Quality Improvements for Anode Coating in Lithium-Ion Battery Cell Manufacturing : A Case Study at Northvolt Labs / Kvalitetsförbättringar för anodbeläggning vid tillverkning av litiumjonbattericeller : En fallstudie på Northvolt LabsKönig, Nikolaj, Norlin, Johan January 2021 (has links)
Lithium-ion batteries (LIB) represent a promising energy storage solution in the pursuit of electrification to combat climate change. In order for LIBs to be used across different industries, they have to be commercially viable. The viability for manufacturing LIBs at scale is increasing, with manufacturing costs decreasing 89% in the last ten years. However, the LIB manufacturing process is complex and can generate large amounts of scrap due to various non-conformities (NCs). Therefore, to further increase the ability to manufacture high-quality LIBs at scale, it is crucial to minimize the occurrence of NCs by understanding their root causes. This thesis examines the characteristics of one of the non-conformities occurring in the electrode coating process, namely the formation of craters on the coated surface of the anode electrode. The thesis was conducted at Northvolt Labs using a DMAIC approach to establish relationships between various process parameters and the formation of craters in two processes, coating, and its precursor process, slurry mixing. Utilizing the data models linear regression, CART regression, regularized linear regression, and a slurry experiment, process parameters and characteristics that affect crater formation were identified. Firstly, from the data models, it was distinguished that the speed of the supply pump used in transferring the slurry from the supply tank to the slot die, and the pressure in the filter pump, have the largest effect on crater formation. Further, the time that the slurry spends in storage, i.e. from a completely mixed slurry batch to it being applied in coating, affects crater formation. In this case, the longer the slurry is stored, the more craters are found. Another notable result is that refilling the coating supply tank induces crater formation. The mentioned results indicate that the various stages of slurry transfer undertaken before coating can result in advantageous conditions for craters to form. Moreover, it was discovered that changes in the loading level of the coated anode surface can indicate crater formation. The slurry experiment discovered that by contaminating the slurry with lubricant grease, NCs with similar characteristics to the crater could be generated. While not likely related to craters, this result provides valuable insights for slurry contamination. In addition to the data models and experiments, actions to facilitate future statistical analysis investigations are proposed. This thesis also proposes actions that can be undertaken to potentially mitigate the formation of craters. Suggested actions include methods to investigate the optimal storage time of the slurry before used in coating. Further, we recommend that the coating process should be monitored through the use of control charts on the loading level measurements of the coated surface. Consequently, large changes in loading level can be detected, entailing potential crater formation. We also propose adding lubricant grease as a potential risk in the PFMEA Northvolt uses for process risk evaluation. This recommendation is also complemented with suggested actions on how to handle the risks of lubricant grease contamination. / Användandet av litiumjonbatterier (LIB) som energilagring är en potentiell lösning för omställning till ett elektrifierat samhälle. Tillverkningsprocessen för LIBs är dock komplex och har en tendens att generera stora mängder kassationer på grund av olika typer av defekter. Denna studie ämnar att undersöka egenskaperna hos en av defekterna som kallas krater som kan förekomma i en av delprocesserna för litiumjonbatteritillverkning, elektrodbeläggning, där batteriets elektroder skapas genom att en blandning av aktiva material appliceras på en metallfolie. Kratern förekommer som en cirkulär form på den belagda ytan av anodelektroden. Studien genomfördes hos batteritillverkaren Northvolt Labs och använde en struktur enligt DMAIC cykeln. Syftet med studien var att fastställa samband mellan olika processparametrar och kraterformation för två olika processer, elektrodbeläggning och dess föregångare, framställning av den aktiva materialblandningen. Genom att använda datamodellerna linjär regression, CART-regression, en regulariserad linjär regression samt ett experiment kunde processparametrar och egenskaper som påverkar kraterbildningen etableras. Resultaten från datamodellerna indikerar att varvtalet i pumpen som tillför ytbeläggningsmaskinen med den aktiva materialblandningen samt trycket i filterpumpen har den största effekten på kraterbildning. Vidare så påverkar tiden som den aktiva materialblandningen lagras innan den används i beläggningsprocessen. Resultaten indikerar att ju längre tid en aktiv materialblandning lagras, desto mer kraterbildning. Samtliga resultat som nämnts ovan anvisar att de olika stadier den aktiva materialblandningen överförs bland olika behållare och verktyg kan ge upphov till kraterbildning. Ytterligare resultat från datamodellerna indikerar att en minskad tjocklek av den belagda ytan, mätt med enheten g/cm2, kan påvisa när kratrar uppstår. Detta resultat kan härledas till att kratrarna orsakar en nedåtbuktning i den belagda ytan. Utifrån experimentet med den aktiva materialblandningen kunde det fastlås att kraterliknande defekter kunde genereras genom att kontaminera blandningen med smörjfett. Dessa defekter är sannolikt inte besläktade med kratern, men dess uppkomst ger värdefulla insikter hur kontaminering kan påverka kvaliteten på den belagda ytan. Utöver resultat från datamodellerna och experimentet så presenterar även denna studie förslag på hur framtida undersökningar av statistisk karaktär kan förbättras. Studien föreslår också konkreta åtanganden som kan genomföras med syfte att reducera kraterbildning. Detta inkluderar hur ett projekt med syfte att fastslå den optimala lagringstiden för den aktiva materialblandningen innan den används i ytbeläggningsprocessen kan utformas. Vidare rekommenderas att ytbeläggningsprocessen övervakas med hjälp av att upprätta styrdiagram för ytbeläggningens nivåförändringar. Följaktligen kan stora förändringar i ytbeläggningens jämnhet detekteras, vilket kan vara en indikator på kraterbildning. Studien rekommenderar också att tillägga kontaminering av smörjfett i den aktiva materialblandningen som en potentiell risk i Northvolts PFMEA. Denna rekommendation kompletteras även med förslag på åtanganden som kan tas för att hantera risken för kontaminering av smörjfett.
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Optimalizace parkovacích stání pro autobusy a nákladní vozidla / Optimization of parking spaces for buses and trucksBedřich, Marek Unknown Date (has links)
Main focus of diploma thesis is optimalization of dimensions stated in parking norm ČSN 73 6056 Parking areas for road vehicles. Goal of the thesis was to optimalize dimensions stated in norm from 2011, eventually come up with a new type of parking space. Thesis is based on recherche, which was done on both previous and actual Czech norms as well as on foreign norms. Change in dimension was possible due to evaluation of swept paths of the individual parking slots. New suggested dimensions are stated in the conclusion.
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An Orthogonally-Fed, Active Linear Phased Array of Tapered Slot AntennasMandeville, Andrew R 01 January 2008 (has links) (PDF)
An active, broadband antenna module amenable for use in low cost phased arrays is proposed. The module consists of a Vivaldi antenna integrated with a frequency conversion integrated circuit. A method of orthogonally mounting endfire antennas onto an array motherboard is developed using castellated vias. A castellated active isolated Vivaldi antenna package is designed, fabricated, and measured. An 8x1 phased array of castellated, active Vivaldi antenna packages is designed and assembled. Each element has approximately one octave of bandwidth centered in X-band, and each is mounted onto a coplanar waveguide motherboard. Radiation patterns of the array are measured at several frequencies and scan angles.
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Miniaturization of Microstrip Patch Antennas for Gps ApplicationsHolland, Steven S 01 January 2008 (has links) (PDF)
The desire to incorporate multiple frequency bands of operation into personal communication devices has led to much research on reducing the size of antennas while maintaining adequate performance. GPS is one such application, where dual frequency operation, bandwidth and circular polarization pose major challenges when using traditional miniaturization techniques. Various loading methods have been studied to reduce the resonant frequency of the antenna – high permittivity dielectric loading, slot loading and cavity loading – while examining their effects on bandwidth and gain. The objective of this thesis is to provide guidelines on what is achievable using these miniaturization methods and insight into how to implement them effectively.
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Design Of A Wideband Dual-polarized Cavity Backed Slot AntennaParyani, Rajesh 01 January 2010 (has links)
A new technique for designing wideband dual-polarized cavity-backed slot antennas is presented. The structure is in the form of a double-resonant, dual-polarized slot antenna backed by a shallow substrate integrated cavity with a depth of approximately one tenth the free space wavelength. The presence of the cavity behind the slot enhances the antenna's directivity and reduces the possibility of surface wave propagation in the antenna substrate when the element is used in an array environment. Moreover, the dual-polarized nature of this radiating element may be exploited to synthesize any desired polarization (vertical, horizontal, RHCP, or LHCP). The double-resonant behavior observed in this substrate-integrated cavity-backed slot antenna (SICBSA) is utilized to enhance its bandwidth compared to a typical cavity-backed slot antenna. A prototype of the proposed antenna is fabricated and tested. Measurement results indicate that a bandwidth of 19%, an average gain of 5.3 dB, and a wideband differential isolation of 30 dB can be achieved using this technique. The principles of operation along with the measurement results of the fabricated prototype are presented and discussed in this dissertation. The SICBSA is investigated as a candidate for use as an array element. A uniform two element phased array is demonstrated to locate the main beam from boresight to thirty degrees. The potential effects of mutual coupling and surface wave propagation are considered and analyzed.
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Dual-Polarized Highly Folded Bowtie Antenna with Slotted Self-Grounded Structure for Sub-6 GHz 5G ApplicationsAlibakhshikenari, M., Virdee, B.S., See, C.H., Shukla, P., Moghaddam, S.M., Zaman, A.U., Shafqaat, S., Akinsolu, M.O., Liu, B., Yang, J., Abd-Alhameed, Raed, Falcone, F., Limiti, E. 26 September 2021 (has links)
Yes / In this paper, a novel dual-polarized highly-folded self-grounded Bowtie antenna that is excited through I-shaped slots is proposed for applications in sub-6GHz 5G multiple-input-multiple-output (MIMO) antenna systems. The antenna consists of two pairs of folded radiation petals whose base is embedded in a double layer of FR-4 substrate with a common ground-plane which is sandwiched between the two substrate layers. The ground-plane is defected with two I-shaped slots located under the radiation elements. Each pair of radiation elements are excited through a microstrip line on the top layer with RF signal that is 180° out of phase with respect to each other. The RF signal is coupled to the pair of feedlines on the top layer through the I-shaped slots from the two microstrip feedlines on the underside of the second substrate. The proposed feed mechanism gets rid of the otherwise bulky balun. The Bowtie antenna is a compact solution with dimensions of 32×32×33.8 mm3. Measured results have verified that the antenna operates over a frequency range of 3.1–5 GHz and exhibits an average gain and antenna efficiency in the vertical and horizontal polarizations of 7.5 dBi and 82.6%, respectively.
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Концептуальная метафора ДЕНЬГИ – ВОДА : магистерская диссертация / The conceptual metaphor MONEY – WATERВан, П., Wang, P. January 2023 (has links)
Магистерская диссертация посвящена исследованию фреймо-слотовой структуры концептуальной метафоры ДЕНЬГИ – ВОДА. В опоре на методику описания концептуальных метафор выделены три ключевых фрейма, отражающих устойчивые метафорические переносы: «Агрегатные состояния воды», «Водные и гидротехнические объекты и явления», «Свойства воды». На богатом текстовом материале из российских газет и журналов последних 30 лет описаны 11 слотов данной концептуальной метафоры. Кроме того, представлены семантические и оценочные варианты реализации концептуальной метафоры ДЕНЬГИ – ЖИДКОСТЬ: ДЕНЬГИ – КРОВЬ, ДЕНЬГИ – СЛЕЗЫ, ДЕНЬГИ – ЖИДКОЕ ЛЕКАРСТВО / ЖИДКИЙ НАРКОТИК; ДЕНЬГИ – МОЛОКО. / The master's thesis is devoted to the study of the frame-slot structure of the conceptual metaphor MONEY – WATER. Based on the methodology of describing conceptual metaphors, three key frames reflecting stable metaphorical transfers are identified: "Aggregate states of water", "Water and hydraulic engineering objects and phenomena", "Properties of water". 11 slots of this conceptual metaphor are described on the rich text material from Russian newspapers and magazines of the last 30 years. In addition, semantic and evaluative options for the implementation of the conceptual metaphor MONEY – LIQUID are presented: MONEY – BLOOD, MONEY – TEARS, MONEY – LIQUID MEDICINE / LIQUID DRUG; MONEY – MILK.
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Eight-Element Dual-Polarized MIMO Slot Antenna System for 5G Smartphone ApplicationsOjaroudi Parchin, Naser, Al-Yasir, Yasir I.A., Ali, Ammar H., Elfergani, Issa T., Noras, James M., Rodriguez, Jonathan, Abd-Alhameed, Raed 02 January 2019 (has links)
Yes / In this paper, we propose an eight-port/four-resonator slot antenna array with a dual-polarized
function for multiple-input-multiple-output (MIMO) 5G mobile terminals. The design is composed of four
dual-polarized square-ring slot radiators fed by pairs of microstrip-line structures. The radiation elements
are designed to operate at 3.6 GHz and are located on the corners of the smartphone PCB. The squarering slot radiators provide good dual-polarization characteristic with similar performances in terms of
fundamental radiation characteristics. In order to improve the isolation and also reduce the mutual coupling
characteristic between the adjunct microstrip-line feeding ports of the dual-polarized radiators, a pair of
circular-ring/open-ended parasitic structures is embedded across each square-ring slot radiator. The −10-dB
impedance bandwidth of each antenna-element is 3.4–3.8 GHz. However, for −6-dB impedance bandwidth,
this value is 600 MHz (3.3–3.9 GHz). The proposed MIMO antenna offers good S-parameters, high-gain
radiation patterns, and sufficient total efficiencies, even though it is arranged on a high-loss FR-4 dielectric.
The SAR function and the radiation characteristics of the proposed design in the vicinity of user-hand/userhead are studied. A prototype of the proposed smartphone antenna is fabricated, and good measurements are
provided. The antenna provides good features with a potential application for use in the 5G mobile terminals. / This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424. / Research Development Fund Publication Prize Award winner, January 2019.
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